In XFIXES mode, are there any hacks to handle cursor transparency (“alpha channel”) exactly?
As of Jan/2005 libvncserver has been modified to allow an alpha channel (i.e. RGBA data) for Rich Cursors. So x11vnc can now send the alpha channel data to libvncserver. However, this data will only be used for VNC clients that do not support the CursorShapeUpdates VNC extension (or have disabled it.) It can be disabled for all clients with the -nocursorshape x11vnc option. In this case the cursor is drawn, correctly blended with the background, into the VNC framebuffer before being sent out to the client. So the alpha blending is done on the x11vnc side. Use the -noalphablend option to disable this behavior (always approximate transparent cursors with opaque RGB values.) The CursorShapeUpdates VNC extension complicates matters because the cursor shape is sent to the VNC viewers supporting it, and the viewers draw the cursor locally. This improves response over slow links. Alpha channel data for these locally drawn cursors is not supported by the VNC protocol. However, in the libvncser
